Coil



Oct. l, 1929. J, sTRAlT 1,729,971

COIL

Fiied May 9, 1925 INVENTOR Patented Oct. 1, 1929 UNITED STATES PATENT OFFICE LACELLE J'. STRAIT, OF FOLSOM CITY, CALIFORNIA, ASSIGNOR 0F ONE-HALF TO AL- BERT C. FLECKENSTEIN, OF FOLSOM CITY, CALIFORNIA COIL Application led May 9,

This invention relates to improvements in coils vadapted to be interposed iny a radio circuit, a telephone circuit or in any other sound transmitting circuit where the results desired are clearance and intensity or volume of sound.

The principal object of my invention is to provide a coil for the purpose, adapted to be interposed in such circuits at a suitable location, so constructed that it ampli-` fies and enlarges the volume of sound produced by reason of the circuit, and at the same time clarifies. the sound, eliminating undesirable noises in the circuit.

I have also produced a coil so wound that with a given length of wire I am enabled to obtain far better results than with an ordinary coil in which the same. length of wire is used.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly effective for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views:

Fig. 1 is a perspective View of my coil with the wrapper partly broken away to show the winding.

Fig. 2 is an enlarged fragmentary diagrammatic view showing the manner of winding the wires.

Fig. 3 is a fragmentary circuit diagram showing the location of my coil in a radio circuit.

Referring now more particularly to the characters of reference on the drawings, in winding the coil 1, I use a single length of wire 2. Instead however of winding this wire as a single continuous length I double it centrally of its length to form two parallel wires connected at one end as at 3. These wires, maintained in superimposed order longitudinally of the coil I then wind in a helical manner to form the coil in the same manner as is done when a single wire is 1925. Serial No. 29,044.

used. The two free ends 4 of the wire are` therefore at the same end of the coil, or at the end thereof opposite to the connection 3 from which the winding operations are begun. The wire is preferably wound in waving or looped form as is ordinarily done in winding the well known honeycomb coils used, in radio sets. In doing this the two parallel wires are looped in. the same direction with each other, as shown by the initial layer or winding A in Fig. 2, while the wires when reaching the connection 3 after passing around the coil, and then forming the second layer or winding B are looped in the opposed or reversed relation to the loops of the layer A as plainly shown. Therefore the wires of the two layers cross each other at the ends of the loops. This alternating reversal of position of the loops of the winds is maintained from one end of the coil to the other. This method of cross-loop winding is already employed in single wirercoils, certain benefits having been discovered by employing this winding arrangement. Straight or concentric winding of the wires may however be employed with good results.

Suitable binding means such as are indicated at 5 are placed about the windings and through the loops from one end to the other when the coil is completed, to prevent movement of the windings relative to each other in any direction. A wrapping 6 of suitable character may then be placed about the windings to completely enclose the same as is commonly done.

While I have shown and above stated that one continuous wire is used, two or more independent wires may of course be employed as long as they are connected together at adjacent ends.

I have found from exhaustive tests that if my coil is interposed in the main lead 7 of the radio aerial 8 between the aerial and the inductance coil 9 of the set, as. indicated in Fig. 3, that the radio reception is greatly improved both as to volume and clarity of sound, while at the same time undesired noises in the circuit are eliminated. Corresponding beneficial results are obtained by Athe firstkwire. In the ordinary single wire coils the positive flow of the current in both wires is in the saine direction. This induced flow therefore acts as a resistance to the flow of the positive current through alternate layers of the wire throughout the length of the coil. This reduces the efficiency of the coil asa sound amplifying medium.

vWith my improved winding arrangement however the Vcurrent is flowing in one vdirection around the coil from one of the ends 4.-

'tion around the coil from said connection 3 to the connection 3 and in the opposite directo the other end 4. Since eachwinding consists of portions, of the two parallel wires,

disposed in vertically alined relation or longitiidinally of the coil, the current will flow in relatively opposite directions in adjacent v parallel wires, and such opposed or reversed direct-ion of flow will be had in alternating order in the wires from one end of the coil to the other. Now just as in the ordinary form of coil above described, the flow of the current in one wire induces a flow in the advjacent wire in the opposite direction. On account of my particular winding arrangement however this induced Vand oppositely flowing current instead of acting against the positive flow of the current in said adjacent wire acts with or in the samedirection as said positive current7 since the latter is normally flowing in the direction opposite to that of the current in the first wire.

There remains of course a slight ohmic resistance but the spurious resistance due to in' j ductance is completely neutralized. The wire for the full length of the coil however will have capacity and with the resistance minimized the introductionof such a non-inducinvention has great value in sound transmitu tive coil just ahead of the receiver will have the effect of increasing the signal strength and clarifying the received signals.

' While I have described my coil as being formed from a single endless wire bentdou` ble on itself before being wound, I have found that the vuse of a lmulti-strand wire gives eX- cellent results.

While a coil constructed according to my ting circuits, its use is not conned to such Vice as substantially fulfills the objects of t-he invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

l. A coil comprising a single continuous wire doubled back on itself substantially midway of its length and the doubled back lengths being maintained in constant parallel relation throughout the coil.

2. A coil comprising a single continuous wire doubled back on itself substantially midway of its length, the doubled back lengths being helically wound in superimposed relation to maintain such lengths in constant parallel relation throughout the coil.

In testimony whereof I aiiiX my signature.

LACELLE J. STRAIT.

lilS 

